The display is typically a component that presents unique difficulties for power management. The display typically represents the largest power consumer after the central processing unit. The display exists solely for the purpose of user interaction and therefore it is only necessary when someone is looking at it. There are many times when a user may turn his attention away from a computer display, perhaps to answer a phone call or get a cup of coffee. There are also scenarios in which the display is only used briefly or not at all for a particular application. For example, someone using a computing device to play music may only interact with the device to select a song.
Therefore, efficient management of display lighting/dimming is typically based on a time-out scheme controlled by user explicit key-board/mouse inputs. Such time-out schemes are typically aimed at predicting the user's need of display via the usage of the computer.